Environmental application of MgMn-layered double oxide for simultaneous efficient removal of tetracycline and Cd pollution: Performance and mechanism. (15th September 2019)

• Record Type: Journal Article
• Authors: Chen, Meiqing; Wu, Pingxiao; Huang, Zhiyan; Liu, Junqin; Li, Yihao; Zhu, Nengwu; Dang, Zhi; Bi, Yinzhi
• Is Part Of: Journal of environmental management. Volume 246(2019)
• Page Start: 164
• Page End: 173
• Publication Date: 2019-09-15
• Subjects: MgMn-Layered double oxide -- Tetracycline -- Peroxymonosulfate -- Cadmium -- Removal; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2019.06.002
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: The MgMn-layered double oxide (MgMn-LDO), which was fabricated by calcining MgMn-layered double hydroxide (MgMn-LDH), was used to remove tetracycline (TC) and cadmium (Cd) pollution. In MgMn-LDO activated peroxymonosulfate (PMS) system, 97.1% of TC was degraded within 20 min. The high oxidizing sites exposed on MgMn-LDO surface played a main role on activating PMS to generate OH, SO4 −, O2 − and 1 O2 (the key species) for TC degradation. MgMn-LDO could keep excellent degradation performance in a wide range of pH (from 4 to 10). The degradation degree of TC in distilled water is basically the same as that in Pearl River water, and even above 80% of TC could be degraded in human urine. The good reusability and high structure stability of MgMn-LDO were further verified. Meanwhile, Cd immobilization on MgMn-LDO reached equilibrium within 10 min, and its maximum fixed quantity was 8.234 mmol g −1 (922.208 mg g −1 ). The outstanding Cd fixed ability resulted from the formation of CdCO3 and Cd (OH)2 . In combined system, the existence of TC promoted the immobilization of Cd on MgMn-LDO. Low concentration of Cd (0.0125 mM) had synergism effect on TC degradation, while high concentration of Cd (0.025 and 0.05 mM) had inhibiting action. Finally, a column filled with MgMn-LDO was designed for repairing TC and Cd pollution hierarchically. This study provided an effective strategy to clean up the organic-heavy metal combined pollution. Graphical abstract: Image 1 Highlights: Large BET with higher oxidizing sites of MgMn-LDO contributed to efficient TC degradation. MgMn-LDO had a wide pH working, practical applicability and high stability. The mechanism of excellent Cd immobilization attributed to form of CdCO3 and Cd (OH)2 . Low concentration of Cd had a synergism effect on TC degradation. Layered repair by column filled with MgMn-LDO toke advantage of the synergism action.